Since 2017, a rationalized curriculum is in effect for the G.C.E (A/L) in the education system in Sri Lanka. It means updating the curriculum that was in implementation.
In this effort, revisions were made in the content, form and curricular materials of the G.C.E (A/L) subjects Physics, Chemistry, and Biology and in concurrence to that, certain changes in the learning teaching methodology, evaluation, n, and assessment were expected. The volume of the subject matter in the curriculum was largely reduced and several alterations in the learning-teaching sequence were also made. A new teachers' handbook was introduced in place of the old curricular material, the teachers' instruction manual.
The teachers' instruction manual contained a line-up of subject matter expected to be learned but the newly introduced teacher's handbook doesn't accommodate any subject matter. Yet, it provides a guideline for teachers to mould the learning events and for evaluation. Though the teacher's hahandbookmplicitly enunciates the limits of the subject by way of the learning outcomes, the teacher's handbook only is not sufficient to identify holistically the confines of the facts. Thus emerged the need for a resource book which simply describes the subject content. This book comes to you as a result of an attempt to fulfil that requirement.
When implementing the previous curricula, the use of internationally recognized standard textbooks published in English has been imperative for Advanced Level Science subjects. But, the contradictions of facts related to subject matter and the inclusion of material beyond the limits of the local curriculum in them, usage of those books was not an easy task for teachers and students.
This book offers students an opportunity to study the relevant subject content in the mother tongue within the limits of the local curriculum. It also provides both students and teachers with a source of reliable information expected by the curriculum dispensing with seedling information from various print media and extra classes.
This book authored by specialist subject teachers and university lecturers is presented to you after the approval of the Academic Affairs Board and the Council of the NIE. Thus it can be recommended as a material of high standard.
Mr. R. S. J. P. Uduporuwa
Director
Department of Science

Guidance
Dr.(Mrs.)T.A.R.J. Gunasekara
Director General
National Institute of Education
Supervision
Mr. R.S.J.P. Uduporuwa
Director, Department of Science
National Institute of Education
Subject Leadership
Miss. P.T.M.K.C. Tennakoon
Assistant Lecturer, Dept. of Science
National Institute of Education
Internal Resource Contribution
Mrs. H.M. Mapagunarathna
Senior Lecturer
National Institute of Education
Mrs D.A.H.U. Sumanasekara
Assistant Lecturer
National Institute of Education
P. Atchuthan
Assistant Lecturer
National Institute of Education
Editorial Panel
Prof. B.G.D.N.K.de Silva - Senior Professor of Molecular Biology,
University of Sri Jayawardanepura - (Unit 02,03)
Prof. S. Abeysinghe - Head of the Department, Department of Botany
The University of Ruhuna - (Unit 02,03,04)
Prof. S. Hettiarachchi - Senior Professor, Department of Biological
Sciences, University of Rajarata - (Unit 02,03,04)
Prof. R.A.S.P. Senanayake - Head of the Department, Department of
Botany, University of Kelaniya - (Unit 03,04)
Prof. D.D. Wickramasinghe - Head of the Department, Department of
Zoology, University of Colombo- (Unit 02)
Prof. A. Pathirathna - Senior Professor, Department of Zoology and
Environmental Management
University of Kelaniya (Unit 05)
Dr.P.L. Hettiarachchi - Senior Lecturer, Department of Biological
Sciences, University of Rajarata (Unit 04)